1. Field of the Invention
This invention relates generally to packaging machines for forming, filling and sealing flexible pouches, and more particularly, to an improved cutoff assembly for such machines.
2. Description of the Related Art
Because of the technical advances in film pouch forming, filling and sealing machines, more and more food and related products, in various states are being packaged in flexible film pouches for ease in shipping, handling and dispensing of such products at a point of use. Known machines to form, fill and seal such pouches usually utilize continuous rolls of heat sealable plastic film, and pouches are generally horizontally or vertically formed in continuous strips from the rolls of plastic film, filled with product, sealed, and then cutoff in a continuous process.
In such known packaging machines which form pouches vertically, i.e., traveling from the top down toward the bottom of the machine, a plurality of streams of formed lower pouches are severed from upper pouches formed from moving streams of front and back heat sealable films by some type of cutoff means at the lower end of the machine, and discharged from the machine at this lower end. The machine is then indexed and the cycle continues. Examples of such vertical packaging machines are disclosed in U.S. Pat. Nos. 4,768,330, 4,845,926, 4,996,819, 5,016,426 and 5,408,807, all of which cover machines produced by W. A. Lane, Inc. of San Bernardino, Calif.
As further discussed in these W. A. Lane patents, the separate cutoff or severing means for the formed pouches, must extend horizontally across the width of the machine and the vertical streams of material being formed, filled and sealed so as to be capable of simultaneously cutting off the formed lower pouches in each of the vertical streams of material.
However, although existing cutoff means work well, they do have numerous drawbacks and/or problems, such as when cutting hard to cut packaging materials, when operating at high speeds, or when environmental conditions such as humidity, temperature, or the like, change. Additionally, over extended periods of use almost all cutoff systems require adjustment, realignment or replacement because of wear and related factors. When known cutoff means become misaligned or wear down, the packaging machines must be stopped and the entire cutoff means either readjusted or replaced. This usually requires special tools, and extended periods of downtime for such machines. Furthermore, in known machines, depending on the materials being cut and the speed of the machines, the known cutoff means quickly become out-of-register, thereby forming unaesthetic and/or unusable pouches. These unusable pouches must be thrown away, resulting in loss of product and waste of materials.
Since known cutoff means have no easy adjusting or aligning mechanisms, much time and effort must be spent in either the readjustment or replacement of the entire cutting means. The resulting downtime of the machine is costly, and can cause shortages and other related problems for the machine user and its customers. Therefore, there exists a need in the package and dispensing art for a cutoff means which may be easily and quickly adjusted, at least in one dimension, and which overcomes the above set drawbacks, as well as other problems, and which may be easily fitted to existing machinery, or integrated into new machines during manufacture.